This tale of sex and darkness is narrated by Lui, an alienated young Japanese woman who becomes disastrously involved with two dangerous men. Lui first meets her boyfriend Ama in a bar after finding herself mesmerised by his forked tongue. She immediately moves in with him and begins following him down the path to body modification by having her tongue pierced and planning a beautiful tattoo for her back. Ama's friend Shiba creates this exquisite tattoo and as he works on it Lui begins an illicit and brutal sexual relationship with him. Then, after a violent encounter on the back streets of Tokyo, Ama goes missing and Lui must face up to her choices.